Thursday, May 9, 2013

Latest BS from climate modelers on Trenberth's 'missing heat'

A new paper published in Geophysical Research Letters attempts to explain how Trenberth's missing heat got lost in the oceans by claiming that the oceans have somehow become more efficient at absorbing heat over the past decade. The authors note that "the rate of increase of global-mean surface air temperature has apparently slowed during the last decade" [to approximately zero], none of the "state-of-the-art" climate models predicted this "hiatus," and that "the models tend to overestimate the [surface air temperature] trend."see also:Dr. Roy Spencer on why the Trenberth hypothesis about "missing heat" is incorrect

Abstract: The rate of increase of global-mean surface air temperature (SATg) has apparently slowed during the last decade [to approximately zero]. We investigated the extent to which state-of-the-art general circulation models (GCMs) can capture this hiatus period by using multi-model ensembles of historical climate simulations. While the SATg linear trend for the last decade is not captured by their ensemble means regardless of differences in model generation and external forcing, it is barely represented by an 11-member ensemble of a GCM, suggesting an internal [natural] origin of the hiatus associated with active heat uptake by the oceans. Besides, we found opposite changes in ocean heat uptake efficiency (κ), weakening in models and strengthening in nature, which explain why the models tend to overestimate the SATg [surface air temperature] trend. The weakening of κ commonly found in GCMs seems to be an inevitable response of the climate system to global warming, suggesting the recovery from hiatus in coming decades.

To summarise, the IPCC have largely ruled out internal climate change, and used physics to exaggerate processes that would normally have little impact on their own, to explain the origin of the climate. In the IPCC’s view, the ocean can store an enormous amount of energy, but at no time can that potential energy influence long term climate change under a dominate positive feedback. Ultimately, with or without a system lag, it all comes down to external forcing. Periods of hiatus /rapid warming, etc. cancel out in the long term. There is no doubt the attribution of 20th century warming has been simple and straight forward due to human emissions.

In contrast to a system depended on positive feedback, the impact of external forcing is reduced with a system based on a negative feedback, and the initial ‘cause’ or ‘origin’ of climate change is far more ambiguous. Unless a specific negative feedback mechanism is known, attribution is near impossible. Attribution is synonymous with positive feedback. As noted by climate researchers, attribution of warming to an internal process such as the ENSO cycle requires a highly sensitive climate with positive feedback to work!

Storch: The first possibility is that less global warming is occurring than expected because greenhouse gases, especially CO2, have less of an effect than we have assumed. The other possibility is that, in our simulations, we have underestimated how much the climate fluctuates owing to natural causes.

SPIEGEL: But it has been climate researchers themselves who have feigned a degree of certainty even though it doesn't actually exist. For example, the IPCC announced with 95 percent certainty that humans contribute to climate change.

Storch: Of course, that evidence presupposed that we had correctly assessed the amount of natural climate fluctuation. Now that we have a new development, we may need to make adjustments.

SPIEGEL: In which areas do you need to improve the models?

Storch:, there is evidence that the oceans have absorbed more heat than we initially calculated. Temperatures at depths greater than 700 meters (2,300 feet) appear to have increased. The only unfortunate thing is that our simulations failed to predict this effect.

SPIEGEL: That doesn't exactly inspire confidence.

Storch: Certainly the greatest mistake of climate researchers has been giving the impression that they are declaring the definitive truth. The end result is foolishness.

Roy W. Spencer, Ph. D. says:September 18, 2013 at 8:48 AMFirst, I would say that deep ocean measurements which claim warming at the rate of 0.02 deg. C/decade are, indeed, speculative. That warming rate is one half (or less) of just the error bars on our global satellite measurements, which (unlike point deep-ocean measurements, which we far and few between 30 years ago) completely cover the Earth every few days.

Second, the 0.055 deg of ocean temperature causing 55 deg. C of atmospheric warming is physically impossible. I know it’s the same amount of energy either way, but making it sound like this is something that could actually happen is irresponsible.

Jim Clarke says:September 18, 2013 at 9:27 AMSorry Dr., but that makes no sense. First of all, a gas or fluid that is warmer than the surrounding gas or fluid will rise (convection). Convective heat transfer does not operate downward. Mixing in the oceans is largely mechanical, where wind, ocean currents and Earth topography cause up-welling and down-welling in various locations. Warm water on the surface of the ocean does not ‘convectively’ move down.

More importantly, we cannot have ‘more heat’ going into the oceans from the atmosphere if there is not ‘more heat’ in the atmosphere. Putting it another way, atmospheric warming cannot make the oceans warmer if there is no atmospheric warming.

Now, if there was a mechanical mechanism in the oceans that periodically absorbed more energy from the atmosphere (via conduction) than average, then you might be able to claim that the lack of atmospheric warming in the last 15 years was due to that mechanism, (but you would still be hard pressed to explain why that energy shows up in the deep ocean but not at the surface).

Conversely, such a mechanism would have to produce a time when the oceans absorbed less energy than average from the atmosphere (resulting in atmospheric warming). Such a mechanism would have to be figured into the calculations for climate sensitivity to atmospheric CO2. The lack of 21st Century warming indicates a cooling mechanism at least as strong as the warming impact of increasing CO2. Consequently, the warm phase of this mechanism would be at least as strong in the other direction, accounting for at least half of the warming of the late 20th century. The result would be a significant reduction in climate sensitivity to CO2.

Consequently, AGW supporters don’t gain anything by arguing that atmospheric warming is disappearing into the oceans. If it is, than climate is not as sensitive to CO2 as the claim. If it is not, than climate is not as sensitive to CO2 as they claim.

No. Heat flows up. The THC is established by cold water sinking, and warm water rising.

To get the heat to the depths requires A) the surface layers absorbing the IR radiation from the GHGs, which is quickly attenuated in the first few millimeters and B) churning of the oceans to convect the heat down without leaving any trace of its passage in the upper layers.

Going back to the immaculate convection, if you will permit a rather crude, and perhaps offensive-to-some, analogy. There is no sign that warm waters ever… er… penetrated through those upper layers, depositing their heat in the ocean’s belly.

ReplyBart says:September 18, 2013 at 11:17 AMThe difference is in conduction versus convection. Conduction is from hot to cold. Convection drives hot up and cold down. The idea that the heat conducted to the depths is so ridiculous it bears no further mention. The notion that it convected there, leaving no trace of its passage, is barely less so.

ReplyStephen Wilde says:September 18, 2013 at 11:45 AMEvaporation pulls energy out of the ocean surface faster than it can be conducted downward, hence the cooler ocean ‘skin’ at the very top of any significant body of water.

That pretty much excludes the possibility of any significant downward conduction.

Bob Tisdale | September 26, 2013 at 1:22 pm | ReplyThere was no reason for Lubos to do the math. The NODC presents vertically averaged temperatures.http://www.nodc.noaa.gov/OC5/3M_HEAT_CONTENT/basin_avt_data.html

I’ve posted about them here:http://bobtisdale.wordpress.com/2013/07/04/rough-estimate-of-the-annual-changes-in-ocean-temperatures-from-700-to-2000-meters-based-on-nodc-data/

Judith writes: “So, can anyone figure out why 0.06C is a big deal for the climate? ”

Nope. Just the typical alarmist nonsense.

And to put it into another perspective, the annual variations in the ocean temperatures at depths of 700-2000 meters (where the mysterious heat is supposed to be hiding) are on the order of thousandths of a deg C per year:http://bobtisdale.files.wordpress.com/2013/07/fig-1-ocean-temp-changes-700-2000m.png